JP2010224594A - Voltage generation circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage generation circuit that outputs a voltage having a positive temperature coefficient, and allowing the positive temperature coefficient to be arbitrarily set. <P>SOLUTION: An inverting input terminal (negative terminal) of an operation amplifier OP1 of a subtraction circuit 16 is connected through a first resistor R7a to a second voltage source 14. A second resistor R8a is connected between the negative terminal and the output terminal. A non-inverting input terminal (positive terminal) of the OP1 is connected through a third resistor R8b to a first voltage source 12. The positive terminal is grounded through a fourth resistor R7b. A voltage Vptat having a positive temperature coefficient is input from the first voltage source 12 to the positive terminal, and a voltage Vpn having a negative temperature coefficient is input from a second voltage source 14 to the negative terminal. The code of the negative temperature coefficient of the voltage Vpn is inverted, and the absolute value of the temperature coefficient of the voltage Vpn is added to the positive temperature coefficient of the voltage Vptat, and a voltage Tout having the positive temperature coefficient is output. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a voltage generation circuit.

  Conventionally, a temperature detection circuit is provided in a semiconductor integrated circuit for the purpose of preventing destruction of the semiconductor integrated circuit due to a temperature rise. The temperature detection circuit includes a PTAT voltage generation circuit that generates a PTAT (proportional-to-absolute-Temperature) voltage proportional to an absolute temperature, a reference voltage generation circuit that generates a reference voltage, and a comparison circuit that compares the outputs of both It is composed of The reference voltage is set in advance according to the PTAT voltage at the temperature T at which the semiconductor integrated circuit can operate. When the temperature rises and the PTAT voltage exceeds the reference voltage, the comparison circuit generates a signal for controlling the operation of the semiconductor integrated circuit (Patent Documents 1 and 2).

  Recently, as a temperature detection circuit capable of highly accurate temperature detection, a temperature detection circuit applying the “principle of the work function of a gate” has been proposed (Patent Document 3). As shown in FIG. 6, the temperature detection circuit includes a first voltage source circuit that outputs a voltage having a positive or negative temperature coefficient, and a second voltage source circuit that outputs a reference voltage having no temperature coefficient. A subtracting circuit for subtracting the output voltage having a positive or negative temperature coefficient from the first voltage source circuit and a reference voltage having no temperature coefficient from the second voltage source circuit; and an output voltage from the subtracting circuit; The comparator circuit is configured to compare with a reference voltage having no temperature coefficient from the second voltage source circuit.

  Svptat, which is a PTAT voltage having a positive or negative temperature coefficient, is applied from the first voltage source circuit to the positive input terminal of the subtraction circuit. Further, the reference voltage Svref having no temperature coefficient generated by the second voltage source circuit is applied to the negative input terminal of the subtraction circuit. The subtracting circuit includes an operational amplifier OP2 and resistors R7, R8, R9, and R10. The operational amplifier OP2 is used as a differential amplifier, and is operated in principle under the conditions of R7 = R9 and R8 = R10. Therefore, the output voltage Tvptat of the operational amplifier OP2 (that is, the output of the subtraction circuit) Tvptat is simply expressed by the following formula (1) obtained by multiplying the differential input (Svptat-Svref) by the resistance ratio (R8 / R7).

            Tvptat = (R8 / R7) * (Svptat-Svref) Equation (1)

  As shown in FIG. 6, the comparison circuit is composed of an operational amplifier OP3. The reference voltage Vref having no temperature coefficient generated by the second voltage source circuit is converted to Tvref by the resistors R4, R5 and R6. The voltage Tvref is applied to the inverting input terminal of the comparison circuit, and the output Tvptat of the subtraction circuit is applied to the non-inverting input terminal of the comparison circuit. Therefore, if the temperature is lower than the set temperature T, Tvref <Tvptat, and the output Tout of the comparator becomes high level (H). On the other hand, when the temperature is higher than the set temperature T, Tvref> Tvptat, and the output Tout of the comparator becomes low level (L).

JP-A-11-103108 JP-A-11-213644 JP 2004-239734 A

  However, in the temperature detection circuit shown in FIG. 6, since the reference voltage Svref does not have a temperature coefficient, as can be seen from the above equation (1), the maximum temperature coefficient of the output Tvptat of the subtraction circuit is the PTAT voltage Svptat. It depends only on the temperature coefficient. Therefore, with this circuit configuration, the temperature coefficient cannot be sufficiently reflected in the output of the subtraction circuit. Further, the output Tvptat of the subtraction circuit depends only on the temperature coefficient of Svptat as shown in the above equation (1). Therefore, since the output voltages Vptat, Vptat 'and Svptat of the first voltage source circuit are affected by the variation of the threshold voltage due to the process factor of the n-type channel field effect transistor M2, the output voltage of the subtraction circuit is similarly affected. I will receive it. Also, as long as it depends only on the temperature coefficient of Svptat, the output voltage of the subtraction circuit does not become an arbitrary value.

  The present invention has been made to solve the above problems, and an object of the present invention is to output a voltage having a positive temperature coefficient and to arbitrarily set the positive temperature coefficient. Is to provide.

  In order to achieve the above object, the invention described in each claim has the following configuration.

  The invention described in claim 1 is a first voltage source that outputs a first voltage having a positive temperature coefficient, a second voltage source that outputs a second voltage having a negative temperature coefficient, an operational amplifier, and 4 And an inverting input terminal of the operational amplifier is connected to the second voltage source via a first resistor, and a second amplifier is connected between the inverting input terminal and the output terminal of the operational amplifier. Two resistors are connected, a non-inverting input terminal of the operational amplifier is connected to the first voltage source via a third resistor having the same magnitude as the second resistor, and the non-inverting input terminal of the operational amplifier is Connected to a reference potential terminal through a fourth resistor having the same magnitude as the first resistor, and inputs the first voltage from the first voltage source and the second voltage from the second voltage source as inputs. Circuit for outputting a third voltage having a temperature coefficient of A voltage generating circuit having a.

  According to a second aspect of the present invention, the first voltage, the second resistance, the third resistance, and the fourth resistance are variable resistances, and the first voltage and the second voltage input to the subtraction circuit. The voltage generation circuit according to claim 1, wherein the weights are different from each other.

  The invention according to claim 3 is the voltage generation circuit according to claim 1 or 2, wherein the reference potential terminal is a ground terminal or a constant potential terminal.

  According to a fourth aspect of the present invention, the first voltage source outputs a voltage having a positive temperature coefficient proportional to the thermal voltage, or a voltage having a positive temperature coefficient proportional to the thermal voltage; The voltage source circuit is configured to output a voltage represented by the sum of the forward voltage of the diode and the second voltage source includes a diode connection and has a negative temperature coefficient generated by the diode. The voltage generation circuit according to any one of claims 1 to 3, wherein the voltage generation circuit includes a voltage source circuit that outputs a voltage.

  The invention described in each claim has the following effects.

  According to the first aspect of the present invention, there is an effect that it is possible to provide a voltage generation circuit capable of outputting a voltage having a positive temperature coefficient and arbitrarily setting the positive temperature coefficient. There is an effect.

  According to the second aspect of the invention, the weighting of the voltage having the positive temperature coefficient and the voltage having the negative temperature coefficient is changed, and the output voltage is increased from 0V in proportion to the temperature. There is an effect that the voltage value can be set arbitrarily.

  According to the third aspect of the present invention, when connected to the constant potential terminal of the reference voltage, an output voltage obtained by adding a constant voltage proportional to the reference voltage to the output voltage when connected to the ground terminal can be obtained. There is an effect that the value of the output voltage can be arbitrarily set while maintaining the positive temperature coefficient of the output voltage.

  According to the fourth aspect of the present invention, there is an effect that the first voltage source and the second voltage source can be configured by a voltage source circuit capable of arbitrarily setting the temperature coefficient of the generated voltage. . In particular, when the first voltage source is composed of a voltage source circuit that outputs a voltage having a positive temperature coefficient proportional to the thermal voltage, the forward voltage of the diode having a positive temperature coefficient proportional to the thermal voltage and the diode The output voltage is not affected by the process factor of the diode as compared with the case where the voltage source circuit is configured to output a voltage represented by the sum of the voltage and the voltage.

It is a schematic block diagram which shows the basic composition of the voltage generation circuit of this invention. 1 is a circuit diagram showing a configuration of a voltage generation circuit according to a first embodiment of the present invention. It is a circuit diagram which shows the structure of the voltage generation circuit which concerns on the 2nd Embodiment of this invention. It is a circuit diagram which shows the structure of the voltage generation circuit which concerns on the 3rd Embodiment of this invention. It is a circuit diagram which shows the structure of the voltage generation circuit which concerns on the 4th Embodiment of this invention. It is a circuit diagram which shows the structure of the temperature detection circuit which concerns on a prior art. It is a graph which shows the temperature characteristic of the various signals of a voltage generation circuit.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

<Basic configuration>
FIG. 1 is a schematic block diagram showing the basic configuration of the voltage generating circuit of the present invention.

  As shown in FIG. 1, a voltage generation circuit 10 of the present invention includes a first voltage source 12 that outputs a voltage Vptat having a positive temperature coefficient, and a second voltage that outputs a voltage Vpn having a negative temperature coefficient. And a subtracting circuit 16 that receives the voltage Vptat from the first voltage source 12 and the voltage Vpn from the second voltage source 14 and outputs a voltage Tout having a positive temperature coefficient. .

  The subtraction circuit 16 is configured as a differential amplifier including an operational amplifier OP1 and four resistors. The inverting input terminal (−) of the operational amplifier OP1 is connected to the second voltage source 14 via the first resistor R7a. A second resistor R8a is connected between the inverting input terminal (−) and the output terminal of the operational amplifier OP1.

  On the other hand, the non-inverting input terminal (+) of the operational amplifier OP1 is connected to the first voltage source 12 via a third resistor R8b having the same size as the second resistor R8a. The non-inverting input terminal (+) of the operational amplifier OP1 is connected to the reference potential terminal via the fourth resistor R7b having the same size as the first resistor R7a. Note that the reference potential terminal includes a ground terminal (reference potential = 0 V).

  Although the first resistor R7a and the fourth resistor R7b are different resistors, the resistance values are the same. Therefore, in FIGS. 2 to 5, the first resistor R7a and the fourth resistor R7b are simply referred to as “R7. Is displayed. Similarly, the second resistor R8a and the third resistor R8b are simply indicated as “R8”.

  Next, the circuit operation of the voltage generation circuit 10 will be described. In the voltage generation circuit 10, the voltage Vptat having a positive temperature coefficient output from the first voltage source 12 is input to the non-inverting input terminal (+) of the operational amplifier OP 1 of the subtraction circuit 16. The voltage Vpn having a negative temperature coefficient output from the second voltage source 14 is input to the inverting input terminal (−) of the operational amplifier OP1 of the subtraction circuit 16.

  The operational amplifier OP1 is an ideal operational amplifier. When the input impedance is infinite (∞), the operational amplifier OP1 is inverted between the first voltage source 12 and the non-inverting input terminal (+) and the second voltage source 14. It can be regarded as a virtual short (virtual short) between the input terminal (−). When the output voltage Tout of the operational amplifier OP1 is derived under the conditions of R7a = R7b = R7 and R8a = R8b = R8, the output voltage Tout is a voltage having a positive temperature coefficient as represented by the following equation (2). A value obtained by subtracting the product of the voltage Vpn having a negative temperature coefficient and the resistance ratio (R8 / R7) from Vptat.

                Tout = Vptat-(R8 / R7) * Vpn equation (2)

  FIG. 7 is a graph showing temperature characteristics of various signals of the voltage generation circuit 10 of the present invention. As can be seen from this graph, the negative temperature coefficient of the voltage Vpn is reversed in sign by subtraction, and the absolute value of the temperature coefficient of the voltage Vpn is added to the positive temperature coefficient of the voltage Vptat to have a positive temperature coefficient. The voltage Tout is output.

  Compared with the temperature detection circuit shown in FIG. 6 that depends only on the temperature coefficient of the voltage Svptat as shown in the above equation (1), it depends on the temperature coefficient of each of the two types of input voltages Vptat and Vpn. Become. Therefore, the positive temperature coefficient of the output voltage Tout can be arbitrarily set by adjusting the temperature coefficients of the input voltages Vptat and Vpn. Moreover, the value of the output voltage Tout can be arbitrarily set by adjusting the resistance ratio (R8 / R7). For example, even when Vptat ≠ Vpn, the resistance ratio (R8 / R7) can be adjusted so that the output voltage increases from 0 V in proportion to the temperature.

<First Embodiment>
(Configuration of voltage generation circuit)
FIG. 2 is a circuit diagram showing the configuration of the voltage generation circuit according to the first embodiment of the present invention.

  The voltage generation circuit 20 according to the first embodiment includes a first voltage source circuit 22 that outputs a voltage having a positive temperature coefficient, and a second voltage source circuit 24 that outputs a voltage having a negative temperature coefficient. And a subtracting circuit 26 that receives the voltage Vptat from the first voltage source circuit 22 and the voltage Vpn from the second voltage source circuit 24 and outputs a voltage Tout having a positive temperature coefficient. . In the present embodiment, the first voltage source circuit 22 corresponds to a “first voltage source”, and the second voltage source circuit 24 corresponds to a “second voltage source”.

  The configuration of the subtracting circuit 26 is the same as that of the subtracting circuit 16 according to the basic configuration. In the present embodiment, the reference potential terminal is a ground terminal, and one end of the fourth resistor R7b is grounded. In the following embodiments, a case where the voltage generation circuit is configured by using a plurality of bipolar transistors will be described. The plurality of bipolar transistors are monolithically formed on the same semiconductor substrate. Hereinafter, the bipolar transistor is simply referred to as “transistor”.

  The first voltage source circuit 22 includes an npn transistor Q1, an npn transistor Q2, a pnp transistor Q3, a pnp transistor Q4, a pnp transistor Q5, a pnp transistor Q6, a pnp transistor Q7, an npn transistor Q8, a resistor R1, a resistor R2, a resistor R3, A resistor R4 and a resistor R5 are provided.

  The base and collector of the transistor Q7 are connected (diode connection). The bases of the transistor Q6 and the transistor Q7 are commonly connected to form a current mirror circuit. One end of a resistor R3 is connected to the collector side of the transistor Q7. The other end of the resistor R3 is grounded. One end of a resistor R5 is connected to the emitter side of the transistor Q6. The other end of the resistor R5 is connected to the power supply Vcc. The transistor Q6, transistor Q7, resistor R3, and resistor R5 constitute a “starting circuit” that starts operation when a power supply voltage is applied.

  The transistor Q1 and the transistor Q2 are a pair of transistors having different current densities. The bases of the transistor Q1 and the transistor Q2 are commonly connected. One end of a resistor R2 is connected to the emitter side of the transistor Q2. The other end of the resistor R2 is grounded. A resistor R1 is connected between a connection point between the emitter of the transistor Q2 and the resistor R2 and the emitter of the transistor Q1.

The transistor Q3 and the diode-connected transistor Q4 are connected in common to form a current mirror circuit so that the collector current I _Q1 of the transistor _Q1 and the collector current I _{Q2 of the} transistor Q2 are equal. The base of the output transistor Q5 is connected to the connection point between the collector of the transistor Q3 and the collector of the transistor Q1.

  One end of a resistor R5 is connected to the emitter side of the transistor Q5. The other end of the resistor R5 is connected to the power supply Vcc. On the collector side of the transistor Q5, a resistor R4 and a diode-connected transistor Q8 are connected in series as a load. The emitter side of the transistor Q8 is grounded. The base of the transistor Q1 and the base of the transistor Q2 are commonly connected to a connection point A between the collector of the transistor Q5 and the resistor R4.

  These transistor Q1, transistor Q2, transistor Q3, transistor Q4, transistor Q5, transistor Q8, resistor R1, resistor R2, resistor R4, and resistor R5 form a “bandgap reference circuit” that generates a voltage having an arbitrary temperature characteristic. It is composed. A voltage Vptat having a positive temperature coefficient is output from a connection point B between the connection point A and the collector of the transistor Q5. The voltage Vptat is input to the non-inverting input terminal (+) of the operational amplifier OP1 of the subtraction circuit 26.

The second voltage source circuit 24, and a current source I ₀ and a diode-connected transistor Q9 is active load. To the collector of the transistor Q9, a current source I ₀ is connected. The emitter of the transistor Q9 is grounded. From the connection point C located between the collector of said current source I ₀ and the transistor Q9, the voltage Vpn is output having a negative temperature coefficient. The voltage Vpn is input to the inverting input terminal (−) of the operational amplifier OP1 of the subtraction circuit 26.
(Operation of voltage generation circuit)
Next, the circuit operation of the voltage generation circuit 20 will be described.

  First, when a voltage is applied to the power supply Vcc, a voltage is applied to the resistor R3 via the transistor Q7, and a slight current Is flows between the transistor Q7 and the resistor R3. The current Is flows to the diode-connected transistor Q8 via the resistor R4 by a current mirror circuit composed of the transistors Q6 and Q7. When a current flows through the transistor Q8, the base-emitter voltage of the diode-connected transistor Q8 is applied to the base terminals of the transistor Q2 and the transistor Q1.

Thereby, the transistor Q1 and the transistor Q2 operate together, and the collector current _IQ1 and the collector current _IQ2 flow. Here, by setting the transistor size of the transistor Q1 to be larger (N times) than that of the transistor Q2, the collector current I _Q1 > the collector current I _Q2 is _satisfied . Since the value of the collector current I _Q1 is large, the base current of the transistor Q5 is pulled, the transistor Q5 operates, and the collector current of the transistor Q5 flows.

If the value of the collector current _IQ1 is sufficiently large, the collector current of the transistor Q5 becomes large, the voltage drop at the resistor R5 cannot be ignored, and the transistor Q6 does not operate. By stopping the operation of the transistor Q6, the transistor Q6 enters a cutoff state in which no current flows through the collector, and the first voltage source circuit 22 operates stably.

The collector currents of the transistors Q1 and Q2 of the first voltage source circuit 22 that have come to operate stably are as follows: collector current I _Q1 = collector current I _Q2 by the current mirror circuit of the transistors Q3 and Q4. 2I _Q1, which is the sum of the collector currents, flows through the resistor R2. The connection point B, the connection point A, and the base of the transistor Q2 are all at the same potential.

Therefore, the output voltage Vptat from the connection point B is the sum of the voltage drop when the above 2I _Q1 flows through the resistor R2 and the base-emitter voltage of the transistor Q2. That is, the output voltage Vptat is a voltage having a positive temperature coefficient proportional to a thermal voltage expressed by kT / q (k is a Boltzmann constant, T is an absolute temperature, and q is an electronic charge amount), and a forward voltage of the diode. As a whole, the voltage has a positive temperature coefficient.

Next, the second voltage source circuit 24, a current flows from the current source _{I 0} to the transistor Q9. Since the transistor Q9 is diode-connected, the base-emitter voltage has a negative temperature coefficient. The base-emitter voltage of the transistor Q9 is output from the connection point C as the output voltage Vpn having a negative temperature coefficient.

  Next, in the subtraction circuit 26, the voltage Vptat having a positive temperature coefficient is input to the non-inverting input terminal (+) of the operational amplifier OP1. The voltage Vpn having a negative temperature coefficient is input to the inverting input terminal (−) of the operational amplifier OP1. According to the above equation (2), the output voltage Tout is a value obtained by subtracting the product of the voltage Vpn and the resistance ratio (R8 / R7) from the voltage Vptat.

  As described above, in the voltage generation circuit 20 of the present embodiment, the positive temperature coefficient of the output voltage Tout can be arbitrarily set by adjusting the temperature coefficients of the input voltages Vptat and Vpn. Further, the value of the output voltage Tout can be arbitrarily set by adjusting the resistance ratio (R8 / R7) so that the output voltage increases in proportion to the temperature from 0V.

<Second Embodiment>
(Configuration of voltage generation circuit)
FIG. 3 is a circuit diagram showing a configuration of a voltage generating circuit according to the second embodiment of the present invention.

  The voltage generation circuit 30 according to the second embodiment includes a first voltage source circuit 32 for generating a voltage having a positive temperature coefficient, and a second voltage source for outputting a voltage having a negative temperature coefficient. The circuit 34, the third voltage source circuit 36 that outputs a voltage having a positive temperature coefficient, the voltage Vptat from the third voltage source circuit 36, and the voltage Vpn from the second voltage source circuit 34 are input. A subtracting circuit 38 that outputs a voltage Tout having a positive temperature coefficient. In the present embodiment, the first voltage source circuit 32 and the third voltage source circuit 36 correspond to a “first voltage source”, and the second voltage source circuit 34 corresponds to a “second voltage source”. To do.

  The voltage generation circuit 30 according to the second embodiment is the same as that in the first embodiment except that the third voltage source circuit 36 is added and the circuit configuration is changed to add the third voltage source circuit 36. Since the configuration is substantially the same as the voltage generation circuit 20 according to FIG.

A second voltage source circuit 34, instead of the current source I ₀ of the second voltage source circuit 24 of the first embodiment uses a pnp transistor Q10. A diode-connected transistor Q9 is connected to the collector side of the transistor Q10. The base of the transistor Q10 is commonly connected to the bases of the transistors Q3 and Q4 of the first voltage source circuit 32. A voltage Vpn having a negative temperature coefficient is output from a connection point D between the collector of the transistor Q10 and the collector of the transistor Q9. The voltage Vpn is input to the inverting input terminal (−) of the operational amplifier OP1 of the subtraction circuit 38.

  The third voltage source circuit 36 includes a pnp transistor Q11 and a resistor R6. One end of a resistor R6 is connected to the collector side of the transistor Q11. The other end of the resistor R6 is grounded. The base of the transistor Q11 is commonly connected to the base of the transistor Q10 and the bases of the transistors Q3 and Q4. That is, the transistors Q3, Q4, Q10, and Q11 constitute a current mirror circuit. A voltage Vptat ′ having a positive temperature coefficient is output from a connection point E between the collector of the transistor Q11 and the resistor R6. The voltage Vptat ′ is input to the non-inverting input terminal (+) of the operational amplifier OP1 of the subtraction circuit 38.

(Operation of voltage generation circuit)
Next, the circuit operation of the voltage generation circuit 30 will be described.

As in the first embodiment, the collector currents of the transistors Q1 and Q2 of the first voltage source circuit 32 that are stably operated are converted into a collector current I _Q1 = by a current mirror circuit of the transistors Q3 and Q4. The collector current _IQ2 is obtained. Further, the collector current of the transistor Q10 and the collector current of the transistor Q11 are equal to the collector current I _Q1 of the transistor Q1 by the current mirror circuit including the transistors Q3, Q4, Q10, and Q11.

In the second voltage source circuit 34, the collector current _{I Q1} of the transistor Q10 flows through the transistor Q9. Since the transistor Q9 is diode-connected, the base-emitter voltage has a negative temperature coefficient. The base-emitter voltage of the transistor Q9 is output from the connection point D as the output voltage Vpn having a negative temperature coefficient.

In the third voltage source circuit 36, the collector current _{I Q1} of the transistor Q11 flows through the resistor R6. The output voltage Vptat ′ having a positive temperature coefficient is a voltage Vptat ′ that can be set to any positive temperature coefficient by the resistance ratio (R6 / R1) with respect to the output voltage Vptat having the positive temperature coefficient of the first embodiment. 'Is output from the connection point E.

  Next, in the subtraction circuit 38, a voltage Vptat ′ having a positive temperature coefficient is input to the non-inverting input terminal (+) of the operational amplifier OP1. The voltage Vpn having a negative temperature coefficient is input to the inverting input terminal (−) of the operational amplifier OP1. According to the above equation (2), the output voltage Tout is a value obtained by subtracting the product of the voltage Vpn and the resistance ratio (R8 / R7) from the voltage Vptat ′.

  As described above, in the voltage generation circuit 30 of the present embodiment, the positive temperature coefficient of the output voltage Tout can be arbitrarily set by adjusting the temperature coefficients of the input voltages Vptat ′ and Vpn. Further, the value of the output voltage Tout can be arbitrarily set by adjusting the resistance ratio (R8 / R7) so that the output voltage increases in proportion to the temperature from 0V.

  In particular, in the present embodiment, the voltage Vpn which is the base-emitter voltage of the transistor Q9 is obtained by using a current mirror circuit in which the bases of the transistors Q1 and Q2 and the bases of the transistors Q10 and Q11 of the bandgap reference circuit are connected in common. Can be stably generated. Further, by connecting the resistor R6 to the collector of the transistor Q11, the positive temperature coefficient of the voltage Vptat ′ can be set to an arbitrary value with the resistance ratio (R6 / R1) without considering the negative temperature coefficient of the transistor Q2. Can be set. Since the adjustment of the temperature coefficient of the input voltage Vptat ′ is facilitated, the setting of the positive temperature coefficient of the output voltage Tout is similarly facilitated.

<Third Embodiment>
(Configuration of voltage generation circuit)
FIG. 4 is a circuit diagram showing a configuration of a voltage generating circuit according to the third embodiment of the present invention.

  The voltage generation circuit 40 according to the third embodiment includes a first voltage source circuit 42 for generating a voltage having a negative temperature coefficient, and a second voltage source for outputting a voltage having a positive temperature coefficient. A circuit 44, and a subtracting circuit 46 that receives the voltage Vptat ′ from the second voltage source circuit 44 and the voltage Vpn from the first voltage source circuit 42 and outputs a voltage Tout having a positive temperature coefficient. I have. In the present embodiment, the second voltage source circuit 44 corresponds to a “first voltage source”, and the first voltage source circuit 42 corresponds to a “second voltage source”.

  The voltage generation circuit 40 according to the third embodiment has a configuration corresponding to the third voltage source circuit 36 of the second embodiment and the second voltage source circuit 24 of the first embodiment. Although the circuit configuration of the first voltage source circuit 22 is changed by omitting the symbol, the same components as the voltage generation circuit 20 according to the first embodiment and the voltage generation circuit 30 according to the second embodiment are used. Are given the same reference numerals and a part of the description is omitted.

  The first voltage source circuit 42 has a configuration in which the resistor R2 is removed from the first voltage source circuit 22 of the first embodiment. That is, the emitter side of the transistor Q2 is grounded, one end of the resistor R1 is connected to the emitter side of the transistor Q1, and the other end of the resistor R1 is grounded. With this connection, the base-emitter voltage of the transistor Q2 is output as a voltage Vpn ′ having a negative temperature coefficient from the connection point B between the collector of the transistor Q5 and the resistor R4. The voltage Vpn ′ is input to the inverting input terminal (−) of the operational amplifier OP1 of the subtraction circuit 46.

  In the second voltage source circuit 44, the second voltage source circuit 24 of the first embodiment is removed, and a configuration corresponding to the third voltage source circuit 36 of the second embodiment is added instead. Is. Specifically, the second voltage source circuit 44 includes a pnp transistor Q11 and a resistor R6. One end of a resistor R6 is connected to the collector side of the transistor Q11. The other end of the resistor R6 is grounded.

The base of the transistor Q11 is commonly connected to the bases of the transistors Q3 and Q4. That is, the transistors Q3, Q4, and Q11 constitute a current mirror circuit. A voltage Vptat ′ having a positive temperature coefficient is output from a connection point E between the collector of the transistor Q11 and the resistor R6. The voltage Vptat ′ is input to the non-inverting input terminal (+) of the operational amplifier OP1 of the subtraction circuit 46.
(Operation of voltage generation circuit)

  Next, the circuit operation of the voltage generation circuit 40 will be described.

As in the first embodiment, the collector currents of the transistors Q1 and Q2 of the first voltage source circuit 42 that are stably operated are converted into a collector current I _Q1 == by the current mirror circuit of the transistors Q3 and Q4. The collector current _IQ2 is obtained. Further, a current mirror circuit consisting of transistors Q3, Q4, and Q11, the collector current of the transistor Q11 is equal to the collector current _{I Q1} of the transistor Q1.

In the first voltage supply circuit 42, the collector current _{I Q1} of the transistor Q4 flows through the transistor Q2. The base-emitter voltage of transistor Q2 has a negative temperature coefficient. The base-emitter voltage of the transistor Q2 is output from the connection point B as the output voltage Vpn ′ having a negative temperature coefficient.

In the second voltage source circuit 44, the collector current _{I Q1} of the transistor Q11 flows through the resistor R6. The output voltage Vptat ′ having a positive temperature coefficient is a voltage Vptat ′ that can be set to any positive temperature coefficient by the resistance ratio (R6 / R1) with respect to the output voltage Vptat having the positive temperature coefficient of the first embodiment. 'Is output from the connection point E.

  Next, in the subtraction circuit 46, the voltage Vptat ′ having a positive temperature coefficient is input to the non-inverting input terminal (+) of the operational amplifier OP1. A voltage Vpn ′ having a negative temperature coefficient is input to the inverting input terminal (−) of the operational amplifier OP1. According to the following formula (3), the output voltage Tout is a value obtained by subtracting the product of the voltage Vpn ′ and the resistance ratio (R8 / R7) from the voltage Vptat ′.

              Tout = Vptat '-(R8 / R7) * Vpn' Equation (3)

  As described above, in the voltage generation circuit 40 of the present embodiment, the positive temperature coefficient of the output voltage Tout can be arbitrarily set by adjusting the temperature coefficients of the input voltages Vptat ′ and Vpn ′. Further, the value of the output voltage Tout can be arbitrarily set by adjusting the resistance ratio (R8 / R7) so that the output voltage increases in proportion to the temperature from 0V.

  In particular, in this embodiment, the power consumption during operation is reduced by reducing the number of transistors and resistors, and the voltage Vptat ′ having a positive temperature coefficient is lower than the voltage Vptat in the first embodiment. You can get it in action.

Similarly to the second embodiment, by connecting the resistor R6 to the collector of the transistor Q11, the voltage Vptat ′ can be set with the resistance ratio (R6 / R1) without considering the negative temperature coefficient of the transistor Q2. The positive temperature coefficient can be set to any value. Since the adjustment of the temperature coefficient of the input voltage Vptat ′ is facilitated, the setting of the positive temperature coefficient of the output voltage Tout is similarly facilitated.
<Fourth embodiment>
FIG. 5 is a circuit diagram showing a configuration of a voltage generating circuit according to the fourth embodiment of the present invention.

  A voltage generation circuit 40A according to the fourth embodiment is a modification of the third embodiment, and similarly to the voltage generation circuit 40, a first voltage source circuit 42, a second voltage source circuit 44, And a subtracting circuit 46A. The voltage generation circuit 40A sets the reference potential = Vref ≠ 0V, except that one end of the fourth resistor R7b (see FIG. 1) connected to the operational amplifier OP1 of the subtraction circuit 46A is connected to the constant potential terminal Vref which is the reference potential terminal. These have the same configuration as the voltage generation circuit 40 according to the third embodiment. Therefore, the same components as those of the voltage generation circuit 40 are denoted by the same reference numerals and description thereof is omitted.

  The subtraction circuit 46A is configured as a differential amplifier including an operational amplifier OP1, a first resistor R7a, a second resistor R8a, a third resistor R8b, and a fourth resistor R7b, similarly to the subtractor circuit 16 having the basic configuration shown in FIG. Has been. The output voltage Vpn ′ having a negative temperature coefficient output from the connection point B of the first voltage source circuit 42 is input to the inverting input terminal (−) of the operational amplifier OP1. The output voltage Vptat ′ having a positive temperature coefficient output from the connection point E of the second voltage source circuit 44 is input to the non-inverting input terminal (+) of the operational amplifier OP1.

  Similar to the subtracting circuit 16 having the basic configuration, the operational amplifier OP1 is an ideal operational amplifier, and assuming that the input impedance is infinite (∞), the operational amplifier is operated under the conditions of R7a = R7b = R7 and R8a = R8b = R8. When the output voltage of OP1 is derived, the output voltage Tout ′ is expressed by the following equation (4).

    Tout '= Vptat'-(R8 / R7) * Vpn '+ (R8 / R7) * Vref formula (4)

  When the output voltage Tout of the voltage generation circuit 40 expressed by the above equation (3) is used, the above equation (4) is transformed into the following equation (5). As can be seen from this equation (5), the output voltage Tout ′ of the voltage generation circuit 40A is obtained by adding a constant voltage proportional to the reference voltage Vref to the output voltage Tout of the voltage generation circuit 40 according to the third embodiment. Value.

              Tout '= Tout + (R8 / R7) * Vref formula (5)

  As described above, in the voltage generation circuit 40A of the present embodiment, the same effect as that of the voltage generation circuit 40 according to the third embodiment is obtained, and the reference voltage is applied to the output voltage Tout of the voltage generation circuit 40. An output voltage Tout ′ obtained by adding a constant voltage proportional to Vref can be obtained. Since the reference voltage Vref does not have a temperature coefficient, the value of the output voltage Tout ′ can be arbitrarily set while maintaining the positive temperature coefficient of the output voltage Tout.

  In the above embodiment, the voltage generation circuit has been described. However, the voltage generation circuit outputs a voltage having a positive temperature coefficient and can arbitrarily set the positive temperature coefficient. In addition to a temperature detector such as a thermometer, it can be used as a temperature detection circuit or a temperature compensation circuit of a semiconductor integrated circuit. In addition, since the output voltage can be arbitrarily set so as to increase in proportion to the temperature from 0 V, it can be widely used as a detection device for detecting a characteristic having temperature dependence.

DESCRIPTION OF SYMBOLS 10 Voltage generation circuit 12 1st voltage source 14 2nd voltage source 16 Subtraction circuit 20 Voltage generation circuit 22 1st voltage source circuit 24 2nd voltage source circuit 26 Subtraction circuit 30 Voltage generation circuit 32 1st voltage source Circuit 34 Second voltage source circuit 36 Third voltage source circuit 38 Subtraction circuit 40 Voltage generation circuit 40A Voltage generation circuit 42 First voltage source circuit 44 Second voltage source circuit 46 Subtraction circuit 46A Subtraction circuit I ₀ Current source OP1 Operational amplifier OP2 Operational amplifier OP3 Operational amplifiers Q1-Q11 Transistors R1-R8 Resistor _Vcc Power supply V _ref Constant potential terminal

Claims (4)

A first voltage source that outputs a first voltage having a positive temperature coefficient;
A second voltage source that outputs a second voltage having a negative temperature coefficient;
The differential amplifier includes an operational amplifier and four resistors, the inverting input terminal of the operational amplifier is connected to the second voltage source via a first resistor, and the inverting input terminal and the output terminal of the operational amplifier And a non-inverting input terminal of the operational amplifier is connected to the first voltage source via a third resistor having the same size as the second resistor. The terminal is connected to a reference potential terminal through a fourth resistor having the same size as the first resistor, and inputs the first voltage from the first voltage source and the second voltage from the second voltage source. A subtracting circuit for outputting a third voltage having a positive temperature coefficient;
A voltage generation circuit comprising:   The first voltage, the second resistance, the third resistance, and the fourth resistance are variable resistors, and the weights of the first voltage and the second voltage input to the subtraction circuit are different. 2. The voltage generation circuit according to 1.   The voltage generation circuit according to claim 1, wherein the reference potential terminal is a ground terminal or a constant potential terminal. The first voltage source is a voltage source circuit that outputs a voltage having a positive temperature coefficient proportional to the thermal voltage, or a sum of a voltage having a positive temperature coefficient proportional to the thermal voltage and a forward voltage of the diode. It consists of a voltage source circuit that outputs the voltage represented,
The said 2nd voltage source is equipped with the diode connection, and was comprised by the voltage source circuit which outputs the voltage which has the negative temperature coefficient produced | generated by the said diode, The any one of Claim 1 to 3 Voltage generation circuit.

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